1. Field of the Invention
The present invention relates to a gamma ray detecting apparatus and a method for detecting a gamma ray using the same, and more particularly, to a gamma ray detecting apparatus and a method of detecting a gamma ray using the same capable of imaging location and distribution of ray sources of the gamma ray by reversely tracking a trace of a secondary electron generated in Compton scattering reaction of a gamma ray emitted from a gamma ray source or nuclear reaction.
2. Description of the Related Art
In general, in cancer treatment using a radiation, it is important to remove a cancer cell and prevent neighboring normal tissues from being damaged by locally transferring radiation energy to only a cancer tissue. Since a photon beam or an electron beam is used in conventional radiation treatment, it is difficult to limitedly apply a beam amount to the cancer tissue.
Meanwhile, in the case of cancer treatment using protons, the beam amount can concentrate on a desired portion and the damage of the neighboring normal tissues can be minimized due to a peculiar energy transfer characteristic called Bragg Peak.
However, up to now, a technology that accurately decides a Bragg Peak location in a patient's body in real time during treatment has not yet be provided, and as a result, a technology has held the limelight, which infers the Bragg Peak location through a distribution of a prompt gamma ray generated by a reaction between the protons and a target material.
In order to infer the Bragg Peak location, a gamma ray emission imaging device constituted by a focusing device and a position sensitive radiation detector is used and in the gamma ray emission imaging device, when the gamma ray emitted from a radiation source passes through the focusing device and thereafter, reacts in the position sensitive radiation detector, data generated at that time is acquired to image a distribution of the radiation source.
However, the existing gamma ray emission imaging device has various problems. In the existing gamma ray emission imaging device, since most gamma rays are removed by the focusing device, it is difficult to acquire high image sensitivity. Further, since the gamma ray is high in transmittance and low in reaction probability, it is difficult to expect high image sensitivity when the gamma ray is directly detected. In the conventional gamma ray emission imaging device, since image resolution and image sensitivity depend on a structure of the focusing device and have a conflicting characteristic to each other, there is a limit that the image resolution or image sensitivity cannot be independently improved.
Moreover, when energy of the gamma ray increases, the performance of the focusing device is rapidly degraded, and as a result, the image resolution is degraded. Therefore, the convention imaging device of the above scheme can be substantially applied to only a gamma ray of 1 MeV or less.
Further, since a target should be scanned while placing a measurement system measuring the gamma ray circularly or rotating the measurement system in order to acquire an image of the ray source emitting the gamma ray in a 3 dimension, there is a limit in minimizing the device and manufacturing cost is also high.